Contrast Enhanced Ultrasonography for Focal Liver Lesions Characterization: Clinical Perspective

Gray-scale and color Doppler ultrasonography have limited accuracy in characterization of focal liver lesions because a significant overlapping exists between the echo pattern and vascularity of benign and malignant lesions. Several clinical studies have demonstrated that characterization of focal liver lesions that are indeterminate at conventional ultrasonography could be improved using microbubble contrast agents with contrast specific modes. In particular, latest generation ultrasound contrast agents allow evaluation of lesion vascularity in real time using low acoustic power contrast specific modes with the resolution afforded with gray-scale imaging. In this review article the enhancement pattern of different types of benign and malignant focal liver lesions using low acoustic power contrast specific modes is described, and the current role of contrast enhanced ultrasonography in liver lesion characterization is discussed.